1. Field
Embodiments of the present invention generally relate to a method and/or device for data communication; for example to a method and/or device for data communication used with a facsimile device capable of automatically determining the type of the facsimile device and properly setting up a function related to the facsimile device.
2. Discussion of the Background
Recently, management systems for image forming apparatuses have enabled managers of one or more image forming apparatuses to remotely manage them via networks using telecommunication devices.
In a typical management system for image forming apparatuses, one or more image forming apparatuses at a plurality of customers' workplaces are connected to a central control unit installed at a service center (i.e., a facility for sales and technical support) via public lines or other communication lines using data communication devices such as communication adapters. The manager can manage the image forming apparatuses from the service center by operating the central control unit.
In such management system, when the data communication device is directly connected to the public line, the central control unit is caused to dial the customer's telephone number (i.e., a telephone number that gives access to the data communication device) and sends a dual-tone multi-frequency (DTMF) signal as a communication identifier for identifying the central control unit (referred to as identification tone signal). By doing so, the central control unit can access to the data communication device.
A drawback of this background management system is high cost as providing access between the central control unit and the data communication device has needed a line dedicated for this purpose.
To eliminate this drawback, an existing management system for image forming apparatuses has made it possible to access the data communication device over an existing line for a different communication apparatus, such as a facsimile device and a telephone device, which is installed at customers' workplace.
Consequently, in this existing management system, the data communication device and the different communication apparatus share the common line. Therefore, the data communication device is joined with the different communication apparatus in addition to the image forming apparatuses supported by the management system.
For example, the data communication device is connected with a communication apparatus having a facsimile function and an image forming apparatus at the customer's side. To access the data communication device, the central control unit is caused to dial the customer's telephone number. In response to the dialing, the communication apparatus receives a ringing signal via the public line. While the communication apparatus goes off-hook to establish connection, the central control unit sends the DTMF signal to be detected by the data communication device. Upon the detection of the DTMF signal, the data communication device disconnects the communication apparatus from the public line to communicate with the central control unit.
In addition, the data communication device is provided with a facsimile priority mode that gives higher priority to transmission of facsimile data than handling of the image forming apparatus. In the facsimile priority mode, when detecting an off-hook state of the communication apparatus, the data communication device terminates communication with the central control unit to allow the communication apparatus to use the line for facsimile transmission.
After terminating the communication with the central control unit, the data communication device transmits an end signal to an exchange for indicating the end of the communication. This end signal represents an on-hook state of a set period of time. Upon receiving the signal, the exchange gets ready for receiving a dialing signal from the communication apparatus.
Such a facsimile priority mode can be used only with communication apparatuses whose facsimile function establishes communication by detecting a dial tone signal (hereinafter referred to as dial tone detection type). The dial tone detection type apparatus starts dialing when detecting a dial tone signal from the line after going off-hook.
Another type of the facsimile function is referred to as blind dialing type. The blind dialing type apparatus starts dialing when a given period of time has elapsed after going off-hook.
This blind dialing type apparatus may fail to correctly transmit leading digits of the dialed number when the dialing is started before the end signal is fully received by the exchange or before the exchange becomes ready for receiving the dialing signal.
To avoid such an incomplete or incorrect transmission of the dialed number that may lead to a wrong transmission, the facsimile priority mode is, in general, not used with the blind dialing type apparatus. Namely, when using the common line with the blind dialing type apparatus, the data communication device is set up to continue communication regardless of the hook state of the blind dialing type apparatus.
Consequently, the facsimile priority mode of the data communication device is turned on or off according to whether the communication apparatus is a blind dialing type or a dial tone detection type. Therefore, correct identification of the communication apparatus type is needed.
To newly install the data communication device, a provider of the management system identifies the type of the communication apparatus at the customer's workplace. By turning on or off the facsimile priority mode, the provider offers an appropriate service in accordance with the type of the communication apparatus.
The communication apparatus type may be easily identified as long as the communication apparatus is a product of the provider of the management system. However, when the customer uses a product manufactured by another company, the identification of the communication apparatus type is practically difficult. As a result, the facsimile priority mode is not used with the communication apparatus manufactured by another company.
In addition, there may be a case where the facsimile priority mode is improperly used with the blind dialing type apparatus. Such case may occur when the customer replaces a dial tone detection type apparatus with a blind dialing type apparatus without disabling the facsimile priority mode to be used with the replaced dial tone detection type apparatus.
These inconveniences accompanying the management system of image forming apparatuses may be solved by providing a mechanism that can automatically determine the type of the communication apparatus and properly set up the facsimile priority mode. Preferably, such a mechanism is included in the data communication device used with the communication apparatus.